I doubt that 'normal people' would be able to commit terrorist attacks because normal people experience empathy which would prevent them from hurting people voluntarily (even soldiers who act under strict orders in a war that is perceived as just are often traumatized by hurting/killing an enemy combatant... and this would be much more severe if victims were known to include innocent people or even children).
The problem is that there is always enough people who are not normal (there is a great book about it by Erich Fromm: The Anatomy of Human Destructiveness) and it's possible to 'make' people into something not normal in psychological sense - i.e. suppress their empathy for certain group of people by some war trauma or conditioning/brainwashing.
BTW, I think that it's a myth that even bad men love their mommas. It depends how you define love. From what I remember based on one psychopath that I know really well he claims that he loves his mother and maybe he even thinks he feels something like that but he acts in such a way that his mother often gets hurt by his actions and he acts with complete disregard of that. Not love in my book.
"Even bad men love their mommas." - Ben Wade (Russell Crowe), 3:10 to Yuma.